<Emphasis Type="Italic">In vitro</Emphasis> iron enrichment experiments in the Prydz Bay,the Southern Ocean: A test of the iron hypothesis

In "high nitrate, low chlorophyll" (HNLC) ocean regions, iron has been typically regarded as the limiting factor for phytoplankton production. This "iron hypothesis" needs to be tested in various oceanic environments to understand the role of iron in marine biological and biogeochemical processes. In this paper, three in vitro iron enrichment experiments were performed in Prydz Bay and at the Polar Front north of the Ross Sea, to study the role of iron on phytoplankton production. At the Polar Front of Ross...     

中国农村居民旅游消费水平及区域差异研究

依据2005年中国农村居民人均纯收入和2005年<中国国内旅游抽样调查资料的相关数据,建立统计模型进行统计分析.结果表明:中国农村居民旅游消费水平有其复杂性,经济收入的高低,对游客人均花费和旅游购买力有一定影响,对出游率影响不大.依据各地农村居民人均纯收入,把中国28个省、自治区、直辖市农村居民旅游消费水平划分为三个等级,加权平均求得各地农村居民出游率、游客人均花费、旅游购买力的平均值.各地分布特征显示,三个层次农村居民出游率无显著差别;旅游中消费和旅游低消费地区三项旅游消费指标均无显著差别;旅游高消费地区与其它两个地区在游客人均花费、旅游购买力方面有显著差别.     

上海市住房价格梯度及其影响因素分析

选择从上海市中心区至宝山区的一条南北向区段,通过采集沿线内环以内、内环和中环之间、中环和外环之间以及外环以外四个区间内二手房、新房的价格样本,分析其价格梯度差,发现二手房价格一般要高于新房价格,但其价格递减速度比新房更快。根据实际情况,提取繁华程度、市场供求比例、地理区位、交通条件、人口状况、基础设施、环境质量七个影响住房价格的主要因子,运用多元回归分析方法对样本区域的房地产价格进行分析,得出了多元线性回归方程,并进行了回归分析效果检验;最后分别运用偏相关系数分析法和单项因子权重度量法来估算各因子的影响程度。结果表明,二手房市场和新房市场具有明显差异,市场供求是影响二手房价格的最主要因子,而环境质量则是影响新开楼盘价格的首要因子;繁华程度和交通条件的重要影响作用在本次回归模型中没有得到验证。     

中国农村宅基地转型的理论与证实

土地利用转型是土地利用变化的表现形式之一,也是由IGBP和IHDP联合发起的全球土地研究计划 (GLP) 的重要研究内容。目前土地利用/覆被变化 (LUCC) 研究仍然有待进一步理论化,在学科综合与集成基础上提出的假设对土地变化科学显得尤为重要。土地利用转型研究需要寻求一种综合的方法,来对社会和环境变化的时间尺度和历史背景进行整合。通过分析特定时期内中国农村建房的影响因素及相应的管理政策,在了解中国农村建房发展过程的基础上,提出了中国农村宅基地转型趋势的理论假设：随着社会经济的发展,农村宅基地在增加的建设用地总量中所占比例将由高逐渐降低,直到这一比例趋向于一个固定值。最后运用长江沿线样带农村宅基地转型研究结果验证了该理论假设。     

城市居住小区环境归属感评价——以大连市为例

研究居民对居住小区环境归属感,进行定量评价并揭示其规律,可为指导城市小区规划设计提供依据。本文以调查问卷的形式,对大连市的居住小区进行调查,充分考虑评价因子的代表性和多层次性的特点,选取5项一级指标和25个单项指标建立评价指标体系;采用层次分析法与地理信息系统软件Surfer 8.0相结合的方法,对大连市居住小区归属感进行初步评价。研究结果表明:影响居住小区归属感的主要因子有舒适感、识别感、安全感、交流感、成就感;大连市居住小区归属感的整体评价较好,市内四区存在差异;归属感的高值区域分布在生态环境风景区、商务活动中心、靠近海岸线的地方及交通便利的地方。     

Climate Warming and Energy Consumed for Winter Heating in Xi'an

 The accumulated negative temperature, the first heating date, the last heating date, heating duration, collective heating area and energy consumption for winter heating in Xi'an during 1986-2002 were comprehensively analyzed. The results show that under the global warming, winter in Xi'an became warmer and heating duration shorter. With the development of economy, the area and energy consumption for collective heating increased continually. In the meantime, the energy consumption per unit area for winter heating decreased year by year, but it did not match the winter temperature well because the energy was not proportionally consumed according to the change of temperature. In order to conserve energy effectively, heating in winter should be timely adjusted according to actual temperature change.     

Study on consumption efficiency of soil water resources in the Yellow River Basin based on regional ET structure

Based on the regional water resources character, the concept of soil water resources is first redefined, and then associated with their transfer relationship in the hydrological cycle, Evapotranspiration (ET)-based consumption structure and consumption efficiency of soil water resources are analyzed. According to ET 's function in productivity, the consumption efficiency of soil water resources is di- vided into three classes: high efficient consumption from vegetation transpiration, low efficient con- sumption from soil evaporation among plants with high vegetation coverage and inefficient consump- tion from soil evaporation among plants with low vegetation coverage and bare soil evaporation. The high efficient and low efficient consumption were further classified as productive consumption. The ineffi- cient consumption is considered non-productive consumption because it is significant in the whole hydrological cycle process. Finally, according to these categories, and employing a WEP-L dis- tributed hydrological model, this paper analyzes the consumption efficiency of soil water resources in the Yel- low River Basin. The results show that there are 2078.89×108 m3 soil water resources in the whole basin. From the viewpoint of consumption structure, the soil water resources are comprised of 381.89×108 m3 transpiration consumption from vegetation and 1697.09×108 m3 evaporation consumption from soil among plants and bare soil. From the viewpoint of consumption efficiency, soil water re- sources are composed of 920.11×108 m3 efficient consumption and 1158.86×108 m3 of inefficient con- sumption. High efficient consumption accounts for 41.5 percent of the total efficient consumption of the whole basin, low efficient for 58.5 percent. Furthermore, consumption efficiency varies by region. Compared with ET from different land use conditions, the whole basin appears to follow the trend of having the greatest proportion of consumption as inefficient consumption, followed by low efficient consumption, and then the least proportion as high efficient consumption. The amount of inefficient consumption in some regions with vegetation is less than in other regions without vegetation. The amount of inefficient consumption in grasslands is much greater than in forestlands. However, the proportion of low efficient consumption is the greatest in crop fields. The amount of high efficient con- sumption in grasslands and forelands is similar to the corresponding low efficient consumption. However, the low efficient consumption in grasslands is larger than in the forelands. Therefore, when adjusting the utilization efficiency of soil water resources, vegetation coverage and plant structure should be modulated in terms of the principle of decreasing inefficient consumption, improving low efficiency ET and increasing high efficiency ET according to area character.     

石羊河流域生态危机的综合治理探讨

综合治理石羊河流域生态危机的思路是:①用一定生活水平下的人均耕地面积阈值和最佳防护效益森林覆盖率理论,确定的耕地面积和配套的防护林体系。②用生物群落类、湿地类及流域经济社会类3大用水阈值组成的生态用水阈值进行水资源配置或调控。调控过程中紧紧抓住人口的环境容量这个关键,用人口环境容量调控和耦合生产及经济规模基础上,通过调控流域内可利用水资源承载力各分量的方式,对水资源配置进行优化,达到遏制生态危机,促进生态和经济可持续发展的目的。     

饵料粒度对玉筋鱼摄食、生长和生态转换效率的影响

在实验室大型玻璃钢水槽中,流水条件下投喂两种不同颗粒大小的卤虫,采用Eggers模型比较了黄海、渤海主要中上层小型鱼类玉筋鱼的摄食、生长和生态转换效率等生态能量学特征.结果表明:投喂颗粒小的幼体卤虫的排空率比投喂颗粒大的成体卤虫的大,分别为0.2136,0.1887.摄食小颗粒幼体卤虫的玉筋鱼的摄食率、生长率和生态转换效率分别为22.53g/(100g·d)(湿质量)或60.14kJ/(100g·d),3.63g/(100g·d)(湿质量)或14.86kJ/(100g·d),16.12%(以湿质量计)或24.70%(以能量计);而摄食大颗粒成体卤虫的玉筋鱼的摄食率、生长率和生态转换效率分别为27.54g/(100g·d)(湿质量)或51.69kJ/(100g·d),4.77g/(100g·d)(湿质量)或19.50(kJ/100g·d),17.31%(以湿质量计)或37.69%(以能量计).摄食成体卤虫的湿重比摄食幼体卤虫的多,而摄食幼体卤虫所含能量比成体卤虫的高;从玉筋鱼的生长情况来看,成体卤虫投喂的效果明显优于幼体卤虫,不管是用湿重还是用能含量来表示,摄食成体卤虫的生长都比摄食幼体的快,摄食成体的生态转化效率也都比摄食幼体的要高.     

许氏帆蚌耗氧率和排氨率研究

采用生态生理学方法研究了水温和体质量对许氏帆蚌(Hyriopsis schlegelii)耗氧率和排氨率的影响,为育珠蚌养殖生理生态学提供基础资料。用生化培养箱控制水温,winkler碘量法、纳氏试剂比色法测定耗氧率和排氨率。结果表明,在实验温度(9~30℃)条件下,许氏帆蚌的耗氧率为2.504~6.76mg/(kg.h),排氨率为1.963~5.689mg/(kg.h),其中耗氧率和排氨率在27℃达到最高值,30℃均开始下降。在适宜的温度范围内,许氏帆蚌的耗氧率和排氨率均与温度成正比,而与体质量呈负相关。